Design And Fabrication Of Semiconductor Bridge Ignitor Integrated With Emi And ESD Protection

Semiconductor bridge（SCB）ignitors are a new type of ignition device developed following the pace of microelectronic manufacture technologies.Such kind of ignitor has shorter working time,higher quality,easier fabrication process and lower power need than conventional ignitor like metal wire.It also takes smaller area and is compatible with conventional integrated circuit（IC）.Cases SCB can be applied includes weapon ignition,airbags triggering in cars and rocket launching,etc.Electromagnetic interference（EMI）and electrostatic discharge（ESD）damage should be prevented to ensure its proper functioning.Therefore,a high-performance SCB integrated with EMI and ESD reinforcement is studied in the thesis.An ESD and EMI circuit which can be integrated with SCB is designed.A pair of back-to-back comb-structure Schottky barrier diodes（SBD）or a transient voltage suppressor（TVS）is used for ESD protection,and a MOS capacitor is used for EMI protection.Cadence simulation is performed to verify the validity of the protection circuit and Silvaco TCAD simulation is performed to optimize the process of fabrication.Based on the study above,polysilicon bridge,SBD and TVS for ESD reinforcement and SCB chip integrated with SBD is fabricated and tested.Simulations show that best parameters for an H-structure SCB are100μm×380μm×2μm（long×width×thickness）and when dopant concentration is～9.13×10¹⁹cm^-3,1Ωresistance can be achieved.Actual measurement shows that 80μm×340μm×2μm SCB with dopant concentration of 10²⁰cm^-3has a 1.2Ωresistance.2n F MOS capacitor is selected for EMI reinforcement of SCB.Simulation results show that 50%of RF signal>20MHz and 95%of signal>100MHz can be filtered.SBD and TVS for ESD protection are designed,manufactured and tested.In simulation,for SBD,16V breakdown voltage can be achieved when the dopant concentration of barrier area is 1×10¹⁵cm^-3and the distance of the electrodes is 2μm.For TVS,9.5V breakdown voltage can be achieved when the dopant concentration of N and P area is 1×10²⁰cm^-3 and 1×10¹⁷cm^-3respectively and the electrode distance is 3μm.While in actual measurement,SBD with barrier area dopant concentration of 1×10¹⁶cm^-3and electrode distance of 11μm can achieve 16V breakdown voltage and TVS with 4μm electrode distance can achieve 14.5V breakdown voltage.SBD fabricated can provide better protection for SCB from 15k V electrostatic discharge compared with TVS.In SCB chip integrated with SBD,resistance of polysilicon bridge and breakdown voltage of SBD are 2Ωand 20V respectively.The paper can provide reference for following researches on SCB in terms of circuit design,selection and structure design of protection device and optimize of fabrication process.